Geographical variation in Japanese cedar shapes soil nutrient dynamics and invertebrate community

Abstract

The aim of this study was to examine whether differences in the provenances of canopy tree species affect the community of soil invertebrates. We used a common garden, where Cryptomeria japonica trees (Yoshino, Yanase, Itoshiro and Yaku) from four provenances were planted separately in each plot. In these plots, we measured the concentration of nutrients in leaves, litter and roots; Sr isotope ratio (87Sr/86Sr) of leaves; root exudation rate of organic acids; exchangeable nutrients in soil and soil parameters such as soil pH; and abundance and composition of soil invertebrates. Some parameters that may affect nutrient dynamics (concentration of nitrogen in roots, root exudation rate of organic acids, tree growth) and concentrations of calcium and phosphorus in leaves and soil were significantly higher in the Yoshino plot than in the other plots. The 87Sr/86Sr of leaves suggested that the cycling of nutrients such as calcium differed significantly between the plots. Furthermore, the abundances of soil invertebrates that are likely to be affected by nutrient concentrations (e.g. soil crustaceans) were significantly higher in the Yoshino plot than in the other plots. The effects of the provenance of a canopy tree species shape the soil invertebrate abundances and composition by altering the concentration of nutrients in the soil.